What is “inference” on the Semantic Web?
Broadly speaking, inference on the Semantic Web can be characterized by discovering new relationships. As described elsewhere in this FAQ, the data is modeled as a set of (named) relationships between resources. “Inference” means that automatic procedures can generate new relationships based on the data and based on some additional information in the form of an ontology or a set of rules. Whether the new relationships are explicitly added to the set of data, or are returned at query time, is simply an implementation issue. A simple example may help. The data set to be considered may include the relationship (Flipper isA Dolphin). An ontology may declare that “every Dolphin is also a Mammal”. That means that a Semantic Web program understanding the notion of “X is also Y” can add to the set of relationships the statement (Flipper isA Mammal), although that was not part of the original data. One can also say that the new relationship was “discovered”.
Broadly speaking, inference on the Semantic Web can be characterized by discovering new relationships. As described elsewhere in this FAQ, the data is modeled as a set of (named) relationships between resources. “Inference” means that automatic procedures can generate new relationships based on the data and based on some additional information in the form of an ontology or a set of rules. Whether the new relationships are explicitly added to the set of data, or are returned at query time, is simply an implementation issue. A simple example may help. The data set to be considered may include the relationships (Flipper isA Dolphin). An ontology may declare that “every Dolphin is also a Mammal”. That means that a Semantic Web program understanding the notion of “X is also Y” can add to the set of relationships the statement (Flipper isA Mammal), although that was not part of the original data. One can also say that the new relationship was “discovered”.
